Tadano GT-550E-2, Operation And Maintenance Manual

Page: 94 / 100

Setting the Crane
The most important factor for safe crane operation is
setting the outriggers on ground firm enough to support
both the mass of the crane and the load to be lifted.
The crane is normally supported by four outriggers dur-
ing operation, but in certain operating positions, a large
part of the crane mass and lifted load mass may end up
being supported by only one outrigger. If this occurs
when the outriggers are set on soft ground, the outrigger
floats may sink into the ground, causing the crane to list
and, in the worst case, overturn.
Some surfaces may appear to be firm, when in fact they
are not hard enough to support the machine. Be espe-
cially careful of the following surfaces:
(1) Asphalt pavement
(2) Sidewalk or other areas with stone pavement
(3) Areas that have been filled in after excavation
(4) Reclaimed land
(5) Areas near the shoulder of a road or the edge of a pit
Preparing the Ground
When it is unavoidable to set the crane on soft ground or
on ground that cannot bear the load of the crane plus a
load to be lifted, carry out the following procedures:
(1) Grade a slope or rough surface so that the crane can
be set in a level position.
(2) Place steel plates or wood blocks on the surfaces
where the outrigger floats are to be located, in order
to distribute the bearing pressure over a larger area.
The steel plates and wood blocks must be sufficiently
strong and large in area and also appropriate for the
ground condition. The outrigger floats must be set at
the center of the plates or blocks.
Outriggers
T038330E
58
Outriggers Outriggers
If the crane is set on inappropriate ground, it is
possible that the crane could overturn. Always set
the crane on firm ground.
WARNING